[PATCH 1/4] cobalt/kernel: pipeline: add abstract synthetic IRQ API

[PATCH 1/4] cobalt/kernel: pipeline: add abstract synthetic IRQ API

[Philippe Gerum]

From: Philippe Gerum <rpm@xenomai.org>

Add wrappers to create "synthetic IRQs" the I-pipe way (used to be
called "virtual IRQs" there). Those interrupt channels can only be
triggered by software, with per-CPU semantics. We use them to schedule
handlers to be run on the in-band execution stage, meaning "secondary
mode" in the Cobalt jargon.

We don't provide for executing handlers on the out-of-band stage,
because Cobalt does not need this.

Signed-off-by: Philippe Gerum <rpm@xenomai.org>
---
 include/cobalt/kernel/ipipe/pipeline/sirq.h | 58 +++++++++++++++++++++
 1 file changed, 58 insertions(+)
 create mode 100644 include/cobalt/kernel/ipipe/pipeline/sirq.h

diff --git a/include/cobalt/kernel/ipipe/pipeline/sirq.h b/include/cobalt/kernel/ipipe/pipeline/sirq.h
new file mode 100644
index 000000000..7c39244f9
--- /dev/null
+++ b/include/cobalt/kernel/ipipe/pipeline/sirq.h
@@ -0,0 +1,58 @@
+/*
+ * SPDX-License-Identifier: GPL-2.0
+ *
+ * Copyright (C) 2020 Philippe Gerum  <rpm@xenomai.org>
+ */
+
+#ifndef _COBALT_KERNEL_IPIPE_SIRQ_H
+#define _COBALT_KERNEL_IPIPE_SIRQ_H
+
+#include <linux/ipipe.h>
+#include <pipeline/machine.h>
+
+/*
+ * Wrappers to create "synthetic IRQs" the I-pipe way (used to be
+ * called "virtual IRQs" there). Those interrupt channels can only be
+ * triggered by software; they have per-CPU semantics. We use them to
+ * schedule handlers to be run on the in-band execution stage, meaning
+ * "secondary mode" in the Cobalt jargon.
+ */
+
+static inline
+int pipeline_create_inband_sirq(irqreturn_t (*handler)(int irq, void *dev_id))
+{
+	int sirq = ipipe_alloc_virq(), ret;
+
+	if (sirq == 0)
+		return -EAGAIN;
+
+	/*
+	 * ipipe_irq_handler_t is close enough to the signature of a
+	 * regular IRQ handler: use the latter in the generic code
+	 * shared with Dovetail.  The extraneous return code will be
+	 * ignored by the I-pipe core.
+	 */
+	ret = ipipe_request_irq(ipipe_root_domain, sirq,
+				(ipipe_irq_handler_t)handler,
+				NULL, NULL);
+	if (ret) {
+		ipipe_free_virq(sirq);
+		return ret;
+	}
+
+	return sirq;
+}
+
+static inline
+void pipeline_delete_inband_sirq(int sirq)
+{
+	ipipe_free_irq(ipipe_root_domain, sirq);
+	ipipe_free_virq(sirq);
+}
+
+static inline void pipeline_post_sirq(int sirq)
+{
+	ipipe_post_irq_root(sirq);
+}
+
+#endif /* !_COBALT_KERNEL_IPIPE_SIRQ_H */
-- 
2.26.2

[PATCH 2/4] cobalt/pipe: pipeline: convert to abstract synthetic IRQ API

[Philippe Gerum]

From: Philippe Gerum <rpm@xenomai.org>

Signed-off-by: Philippe Gerum <rpm@xenomai.org>
---
 kernel/cobalt/pipe.c | 21 +++++++++------------
 1 file changed, 9 insertions(+), 12 deletions(-)

diff --git a/kernel/cobalt/pipe.c b/kernel/cobalt/pipe.c
index 8044c3ff7..9465fb2da 100644
--- a/kernel/cobalt/pipe.c
+++ b/kernel/cobalt/pipe.c
@@ -32,6 +32,7 @@
 #include <cobalt/kernel/sched.h>
 #include <cobalt/kernel/heap.h>
 #include <cobalt/kernel/pipe.h>
+#include <pipeline/sirq.h>
 
 static int xnpipe_asyncsig = SIGIO;
 
@@ -145,7 +146,7 @@ static inline void xnpipe_dequeue_all(struct xnpipe_state *state, int mask)
 	__sigpending;							\
 })
 
-static void xnpipe_wakeup_proc(unsigned int virq, void *arg)
+static irqreturn_t xnpipe_wakeup_proc(int sirq, void *dev_id)
 {
 	struct xnpipe_state *state;
 	unsigned long rbits;
@@ -219,11 +220,13 @@ check_async:
 	}
 out:
 	xnlock_put_irqrestore(&nklock, s);
+
+	return IRQ_HANDLED;
 }
 
 static inline void xnpipe_schedule_request(void) /* hw IRQs off */
 {
-	ipipe_post_irq_root(xnpipe_wakeup_virq);
+	pipeline_post_sirq(xnpipe_wakeup_virq);
 }
 
 static inline ssize_t xnpipe_flush_bufq(void (*fn)(void *buf, void *xstate),
@@ -1157,17 +1160,13 @@ int xnpipe_mount(void)
 		return -EBUSY;
 	}
 
-	xnpipe_wakeup_virq = ipipe_alloc_virq();
-	if (xnpipe_wakeup_virq == 0) {
+	xnpipe_wakeup_virq = pipeline_create_inband_sirq(xnpipe_wakeup_proc);
+	if (xnpipe_wakeup_virq < 0) {
 		printk(XENO_ERR
 		       "unable to reserve synthetic IRQ for message pipes\n");
-		return -EBUSY;
+		return xnpipe_wakeup_virq;
 	}
 
-	ipipe_request_irq(ipipe_root_domain,
-			  xnpipe_wakeup_virq,
-			  xnpipe_wakeup_proc,
-			  NULL, NULL);
 	return 0;
 }
 
@@ -1175,9 +1174,7 @@ void xnpipe_umount(void)
 {
 	int i;
 
-	ipipe_free_irq(ipipe_root_domain,
-		       xnpipe_wakeup_virq);
-	ipipe_free_virq(xnpipe_wakeup_virq);
+	pipeline_delete_inband_sirq(xnpipe_wakeup_virq);
 
 	unregister_chrdev(XNPIPE_DEV_MAJOR, "rtpipe");
 
-- 
2.26.2

[PATCH 3/4] cobalt/registry: pipeline: convert to abstract synthetic IRQ API

[Philippe Gerum]

From: Philippe Gerum <rpm@xenomai.org>

Signed-off-by: Philippe Gerum <rpm@xenomai.org>
---
 kernel/cobalt/registry.c | 28 ++++++++++++----------------
 1 file changed, 12 insertions(+), 16 deletions(-)

diff --git a/kernel/cobalt/registry.c b/kernel/cobalt/registry.c
index 7f7cb9eea..816102f7a 100644
--- a/kernel/cobalt/registry.c
+++ b/kernel/cobalt/registry.c
@@ -22,6 +22,7 @@
 #include <cobalt/kernel/registry.h>
 #include <cobalt/kernel/thread.h>
 #include <cobalt/kernel/assert.h>
+#include <pipeline/sirq.h>
 
 /**
  * @ingroup cobalt_core
@@ -61,7 +62,7 @@ static struct xnsynch register_synch;
 
 static void proc_callback(struct work_struct *work);
 
-static void registry_proc_schedule(unsigned int virq, void *arg);
+static irqreturn_t registry_proc_schedule(int virq, void *dev_id);
 
 static LIST_HEAD(proc_object_list);	/* Objects waiting for /proc handling. */
 
@@ -123,17 +124,12 @@ int xnregistry_init(void)
 		return ret;
 	}
 
-	proc_virq = ipipe_alloc_virq();
-	if (proc_virq == 0) {
+	proc_virq = pipeline_create_inband_sirq(registry_proc_schedule);
+	if (proc_virq < 0) {
 		xnvfile_destroy_regular(&usage_vfile);
 		xnvfile_destroy_dir(&registry_vfroot);
-		return -EBUSY;
+		return proc_virq;
 	}
-
-	ipipe_request_irq(ipipe_root_domain,
-			  proc_virq,
-			  registry_proc_schedule,
-			  NULL, NULL);
 #endif /* CONFIG_XENO_OPT_VFILE */
 
 	next_object_stamp = 0;
@@ -155,8 +151,7 @@ int xnregistry_init(void)
 #ifdef CONFIG_XENO_OPT_VFILE
 		xnvfile_destroy_regular(&usage_vfile);
 		xnvfile_destroy_dir(&registry_vfroot);
-		ipipe_free_irq(ipipe_root_domain, proc_virq);
-		ipipe_free_virq(proc_virq);
+		pipeline_delete_inband_sirq(proc_virq);
 #endif /* CONFIG_XENO_OPT_VFILE */
 		return -ENOMEM;
 	}
@@ -202,8 +197,7 @@ void xnregistry_cleanup(void)
 	xnsynch_destroy(&register_synch);
 
 #ifdef CONFIG_XENO_OPT_VFILE
-	ipipe_free_irq(ipipe_root_domain, proc_virq);
-	ipipe_free_virq(proc_virq);
+	pipeline_delete_inband_sirq(proc_virq);
 	flush_scheduled_work();
 	xnvfile_destroy_regular(&usage_vfile);
 	xnvfile_destroy_dir(&registry_vfroot);
@@ -332,13 +326,15 @@ static void proc_callback(struct work_struct *work)
 	up(&export_mutex);
 }
 
-static void registry_proc_schedule(unsigned int virq, void *arg)
+static irqreturn_t registry_proc_schedule(int virq, void *dev_id)
 {
 	/*
 	 * schedule_work() will check for us if the work has already
 	 * been scheduled, so just be lazy and submit blindly.
 	 */
 	schedule_work(&registry_proc_work);
+
+	return IRQ_HANDLED;
 }
 
 static int registry_export_vfsnap(struct xnobject *object,
@@ -473,7 +469,7 @@ static inline void registry_export_pnode(struct xnobject *object,
 	object->pnode = pnode;
 	list_del(&object->link);
 	list_add_tail(&object->link, &proc_object_list);
-	ipipe_post_irq_root(proc_virq);
+	pipeline_post_sirq(proc_virq);
 }
 
 static inline void registry_unexport_pnode(struct xnobject *object)
@@ -489,7 +485,7 @@ static inline void registry_unexport_pnode(struct xnobject *object)
 			object->pnode->ops->touch(object);
 		list_del(&object->link);
 		list_add_tail(&object->link, &proc_object_list);
-		ipipe_post_irq_root(proc_virq);
+		pipeline_post_sirq(proc_virq);
 	} else {
 		/*
 		 * Unexporting before the lower stage has had a chance
-- 
2.26.2

[PATCH 4/4] cobalt/select: pipeline: convert to abstract synthetic IRQ API

[Philippe Gerum]

From: Philippe Gerum <rpm@xenomai.org>

Signed-off-by: Philippe Gerum <rpm@xenomai.org>
---
 kernel/cobalt/select.c | 22 ++++++++++------------
 1 file changed, 10 insertions(+), 12 deletions(-)

diff --git a/kernel/cobalt/select.c b/kernel/cobalt/select.c
index f45905112..bd790affe 100644
--- a/kernel/cobalt/select.c
+++ b/kernel/cobalt/select.c
@@ -23,6 +23,7 @@
 #include <cobalt/kernel/sched.h>
 #include <cobalt/kernel/synch.h>
 #include <cobalt/kernel/select.h>
+#include <pipeline/sirq.h>
 
 /**
  * @ingroup cobalt_core
@@ -398,12 +399,12 @@ void xnselector_destroy(struct xnselector *selector)
 
 	xnlock_get_irqsave(&nklock, s);
 	list_add_tail(&selector->destroy_link, &selector_list);
-	ipipe_post_irq_root(deletion_virq);
+	pipeline_post_sirq(deletion_virq);
 	xnlock_put_irqrestore(&nklock, s);
 }
 EXPORT_SYMBOL_GPL(xnselector_destroy);
 
-static void xnselector_destroy_loop(unsigned int virq, void *arg)
+static irqreturn_t xnselector_destroy_loop(int virq, void *dev_id)
 {
 	struct xnselect_binding *binding, *tmpb;
 	struct xnselector *selector, *tmps;
@@ -438,25 +439,22 @@ static void xnselector_destroy_loop(unsigned int virq, void *arg)
 	}
 out:
 	xnlock_put_irqrestore(&nklock, s);
+
+	return IRQ_HANDLED;
 }
 
 int xnselect_mount(void)
 {
-	deletion_virq = ipipe_alloc_virq();
-	if (deletion_virq == 0)
-		return -EBUSY;
-
-	ipipe_request_irq(ipipe_root_domain,
-			deletion_virq,
-			xnselector_destroy_loop,
-			NULL, NULL);
+	deletion_virq = pipeline_create_inband_sirq(xnselector_destroy_loop);
+	if (deletion_virq < 0)
+		return deletion_virq;
+
 	return 0;
 }
 
 int xnselect_umount(void)
 {
-	ipipe_free_irq(ipipe_root_domain, deletion_virq);
-	ipipe_free_virq(deletion_virq);
+	pipeline_delete_inband_sirq(deletion_virq);
 	return 0;
 }
 
-- 
2.26.2

Re: [PATCH 1/4] cobalt/kernel: pipeline: add abstract synthetic IRQ API

[Jan Kiszka]

On 17.01.21 16:25, Philippe Gerum wrote:
> From: Philippe Gerum <rpm@xenomai.org>
> 
> Add wrappers to create "synthetic IRQs" the I-pipe way (used to be
> called "virtual IRQs" there). Those interrupt channels can only be
> triggered by software, with per-CPU semantics. We use them to schedule
> handlers to be run on the in-band execution stage, meaning "secondary
> mode" in the Cobalt jargon.
> 
> We don't provide for executing handlers on the out-of-band stage,
> because Cobalt does not need this.
> 
> Signed-off-by: Philippe Gerum <rpm@xenomai.org>
> ---
>  include/cobalt/kernel/ipipe/pipeline/sirq.h | 58 +++++++++++++++++++++
>  1 file changed, 58 insertions(+)
>  create mode 100644 include/cobalt/kernel/ipipe/pipeline/sirq.h
> 
> diff --git a/include/cobalt/kernel/ipipe/pipeline/sirq.h b/include/cobalt/kernel/ipipe/pipeline/sirq.h
> new file mode 100644
> index 000000000..7c39244f9
> --- /dev/null
> +++ b/include/cobalt/kernel/ipipe/pipeline/sirq.h
> @@ -0,0 +1,58 @@
> +/*
> + * SPDX-License-Identifier: GPL-2.0
> + *
> + * Copyright (C) 2020 Philippe Gerum  <rpm@xenomai.org>
> + */
> +
> +#ifndef _COBALT_KERNEL_IPIPE_SIRQ_H
> +#define _COBALT_KERNEL_IPIPE_SIRQ_H
> +
> +#include <linux/ipipe.h>
> +#include <pipeline/machine.h>
> +
> +/*
> + * Wrappers to create "synthetic IRQs" the I-pipe way (used to be
> + * called "virtual IRQs" there). Those interrupt channels can only be
> + * triggered by software; they have per-CPU semantics. We use them to
> + * schedule handlers to be run on the in-band execution stage, meaning
> + * "secondary mode" in the Cobalt jargon.
> + */
> +
> +static inline
> +int pipeline_create_inband_sirq(irqreturn_t (*handler)(int irq, void *dev_id))
> +{
> +	int sirq = ipipe_alloc_virq(), ret;

Correct but uncommon style. I've broken that up into two lines.

Jan

> +
> +	if (sirq == 0)
> +		return -EAGAIN;
> +
> +	/*
> +	 * ipipe_irq_handler_t is close enough to the signature of a
> +	 * regular IRQ handler: use the latter in the generic code
> +	 * shared with Dovetail.  The extraneous return code will be
> +	 * ignored by the I-pipe core.
> +	 */
> +	ret = ipipe_request_irq(ipipe_root_domain, sirq,
> +				(ipipe_irq_handler_t)handler,
> +				NULL, NULL);
> +	if (ret) {
> +		ipipe_free_virq(sirq);
> +		return ret;
> +	}
> +
> +	return sirq;
> +}
> +
> +static inline
> +void pipeline_delete_inband_sirq(int sirq)
> +{
> +	ipipe_free_irq(ipipe_root_domain, sirq);
> +	ipipe_free_virq(sirq);
> +}
> +
> +static inline void pipeline_post_sirq(int sirq)
> +{
> +	ipipe_post_irq_root(sirq);
> +}
> +
> +#endif /* !_COBALT_KERNEL_IPIPE_SIRQ_H */
> 

-- 
Siemens AG, T RDA IOT
Corporate Competence Center Embedded Linux

Re: [PATCH 4/4] cobalt/select: pipeline: convert to abstract synthetic IRQ API

[Jan Kiszka]

On 17.01.21 16:25, Philippe Gerum wrote:
> From: Philippe Gerum <rpm@xenomai.org>
> 
> Signed-off-by: Philippe Gerum <rpm@xenomai.org>
> ---
>  kernel/cobalt/select.c | 22 ++++++++++------------
>  1 file changed, 10 insertions(+), 12 deletions(-)
> 
> diff --git a/kernel/cobalt/select.c b/kernel/cobalt/select.c
> index f45905112..bd790affe 100644
> --- a/kernel/cobalt/select.c
> +++ b/kernel/cobalt/select.c
> @@ -23,6 +23,7 @@
>  #include <cobalt/kernel/sched.h>
>  #include <cobalt/kernel/synch.h>
>  #include <cobalt/kernel/select.h>
> +#include <pipeline/sirq.h>
>  
>  /**
>   * @ingroup cobalt_core
> @@ -398,12 +399,12 @@ void xnselector_destroy(struct xnselector *selector)
>  
>  	xnlock_get_irqsave(&nklock, s);
>  	list_add_tail(&selector->destroy_link, &selector_list);
> -	ipipe_post_irq_root(deletion_virq);
> +	pipeline_post_sirq(deletion_virq);
>  	xnlock_put_irqrestore(&nklock, s);
>  }
>  EXPORT_SYMBOL_GPL(xnselector_destroy);
>  
> -static void xnselector_destroy_loop(unsigned int virq, void *arg)
> +static irqreturn_t xnselector_destroy_loop(int virq, void *dev_id)
>  {
>  	struct xnselect_binding *binding, *tmpb;
>  	struct xnselector *selector, *tmps;
> @@ -438,25 +439,22 @@ static void xnselector_destroy_loop(unsigned int virq, void *arg)
>  	}
>  out:
>  	xnlock_put_irqrestore(&nklock, s);
> +
> +	return IRQ_HANDLED;
>  }
>  
>  int xnselect_mount(void)
>  {
> -	deletion_virq = ipipe_alloc_virq();
> -	if (deletion_virq == 0)
> -		return -EBUSY;
> -
> -	ipipe_request_irq(ipipe_root_domain,
> -			deletion_virq,
> -			xnselector_destroy_loop,
> -			NULL, NULL);
> +	deletion_virq = pipeline_create_inband_sirq(xnselector_destroy_loop);
> +	if (deletion_virq < 0)
> +		return deletion_virq;
> +
>  	return 0;
>  }
>  
>  int xnselect_umount(void)
>  {
> -	ipipe_free_irq(ipipe_root_domain, deletion_virq);
> -	ipipe_free_virq(deletion_virq);
> +	pipeline_delete_inband_sirq(deletion_virq);
>  	return 0;
>  }
>  
> 

Thanks, all 4 applied.

Jan

-- 
Siemens AG, T RDA IOT
Corporate Competence Center Embedded Linux